Synergistic toughening mechanism in 3Y–TZP/Nb composites

• Published in: Acta materialia Vol. 55; no. 17; pp. 5924 - 5933
• Main Authors: Bartolomé, J.F., Gutiérrez-González, C.F., Pecharromán, C., Moya, J.S.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.10.2007; Elsevier Science
• Subjects: Applied sciences; Ceramic–matrix composites; Cermets; Crack bridging; Exact sciences and technology; Fractures; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Microstructure; Niobium; Reinforcement; Surface cracks; Tetragonal zirconia polycrystals; Tolerances; Toughening; Toughness; Yttria stabilized zirconia; Ceramic–matrix composites; Toughness; Cermets; Microstructure; Cermet; Rupture; Mechanical properties; Ceramic-matrix composites; Ceramic materials; Synergism; Composite material; Mechanism; Fracture toughness
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2007.07.004

This paper focuses on the study of the flaw tolerance and resistance curve behaviour ( R-curve) in 3Y–TZP/Nb composites containing indentation-induced small surface cracks. It has been found that toughening and resistance curve behaviour occurs as a result of the combined effects of crack bridging and transformation toughening. The ZrO 2–Nb composites are described as synergistically toughened composites due to anticipated interactions between crack bridging and stress-induced phase transformation. It has been found that these interactions produce a notable increase in toughness ( K ss ≈ 13 MPa m 1/2) greater than the sum of the combination that would be provided separately by the two types of reinforcement.